In all natural languages, meanings are expressed by putting words together into grammatical
units, or phrases.
For the purposes of this video, we’re going to focus on three basic types of phrases:
Possessive phrases, like “the woman’s dog”, where one noun possesses another,
adpositional phrases, like “in the house”, where a noun serves as a referent for an adposition,
and verb phrases, like “I see the dog”, where the action of the verb received by an
object.
Each of these phrases contains what’s called a “head”, which is kind of difficult to
define without going into complex theoretical stuff, but to put it very simply, the head
is essentially the word that defines what type of phrase is occurring, and that must
be present for the phrase to exist, while the other word in the phrase is called the
dependent, which just serves to modify the head and can’t occur without a head to refer
to.
For example, in a possessive phrase like “The woman’s dog”, the fact that the dog belongs
to the woman is just an optional bit of extra information, and omitting it just leaves “the
dog”, which is still a grammatically valid thing to say, whereas “the woman’s”
can’t stand on its own without some other noun to possess, so in possessive phrases,
the thing being possessed, sometimes called the possessum or possessee, is the head, while
its possessor is the dependent.
In adpositional phrases, the head is the adposition, since by definition, it’s not an adpositional
phrase if there’s no adposition, and the dependent is therefore the object or referent
of the adposition.
Finally, in the verb phrase, the head is the verb, and the dependent is the direct object,
and depending on exactly what definition you’re using, the subject may or may not also be
considered a dependent, but we’ll focus just on the direct object for clarity.
Heads and dependents are usually brought up in the context of head-initial and head-final
syntax, which describes how languages have a tendency to keep the order of the head and
dependent consistent across all types of phrases, but the way a language treats heads and dependents
will also surface in its morphology.
When putting phrases together, most languages will include some sort of marking to specify
what type of phrase is occurring and the role of each of the constituents within the phrase.
This marking will most often occur as an affix on either the head or the dependent, giving
rise to two possible systems of marking.
Let’s go through some examples of each of these phrases and contrast how they’re handled
between dependent-marking and head-marking systems.
Starting off with a possessive phrase, like “the woman’s dog”, in a dependent-marking
language, we’d take the possessor, in this case the woman, and attach an affix that marks
it as the possessor the other noun in the phrase.
You’ll notice that, not only is that exactly what English does with its apostrophe s suffix,
but also, by definition, that’s exactly what a genitive case marker does, so languages
like Latin, Greek, and Russian can all be said to be dependent-marking in possessive
phrases.
Meanwhile, in a head-marking language, we’d take the possessed noun, in this case the
dog, and attach an affix that marks it as being possessed by the other noun.
This may just occur as just a single marker like the construct state in many of the Semitic
languages, but it’s also very common for this marking to agree with the possessor in
person, number, and possibly gender if the language has it, so in a language like Classical
Nāhuatl, to say “my dog”, one would simply take the word “chichi”, “dog” and
apply a 1st person possessive marker to get “nochichi”, whereas “your dog” would
be “mochichi”, his, her, or it’s dog would be “īchichi”, and to say “The
woman’s dog”, you would say “īchichi cihuatl”, which would literally be “her-dog
the woman”.
Next up, in an adpositional phrase like “in the house”, we’d expect a dependent-marking
language to take the house and mark it as being the object of the adposition.
Specifically, the way this is usually done is that the adposition will assign a particular
case to its object, which will vary from language to language and may also depend which adposition
is being used and what meaning is being conveyed.
For instance, to say “in the house” in Latin, the preposition “in” assigns the
ablative case, but to say “into the house”, the same preposition now applies the accusative
case, whereas “toward the house” still assigns the accusative, but instead uses a
different preposition.
Meanwhile in a head-marking language, we would expect the adposition to be marked as being
the head of the phrase, which once again will usually agree with the object in person, number,
and possibly gender, so in Nāhuatl to say “in the house”, you’d say, “īhtic
calli” literally “inside-it the house”.
By the way, it’s very common for the morphology taken by these inflecting adpositions to be
identical to those taken by the head in possessive phrases, for the simple reason that adpositional
phrases commonly evolve from possessive ones.
Finally, for verb phrases, a dependent-marking language will usually take the direct object
and mark it as being the dependent of the verb phrase, which, again, by definition,
is what an accusative case marker does, so, in case you hadn’t already figured it out,
the plot twist is that dependent-marking is functionally identical to case-marking, so
the vast majority of languages that use case-markers can be said to be dependent-marking.
On the other hand, head-marking languages will take the head, the verb, and apply a
marker that signifies that the verb has a direct object, which, once again, will usually
agree with the object in person, number, and potentially gender.
Also, on a related note, if a verb is going to inflect to agree with the object, then
it will almost certainly agree with the subject as well, a feature called polypersonal agreement,
so in Nāhuatl, to say “I see the dog”, you would say “I-see-it the dog”.
So, these are the two prototypical strategies for dependent-marking and head-marking.
Just like head-initial vs head-final syntax, most languages will show a strong preference
for one over the other, partly because of the way these systems come about.
Cases routinely evolve from adpositions that affix onto their accompanying nouns, while
head-marking strategies typically evolve from pronouns that fuse onto the words they occur
with, so usually only one of these two developments will take place, but occasionally, more mixed
systems can occur as well: Swahili makes ample use of polypersonal agreement in its verb
system like a head-marking language, but also handles possession by way of genitive pronouns
like a dependent-marking language, while Hungarian has a rich case inventory to mark most roles,
except in possessive phrases where it instead marks the possessed noun with an affix that
agrees with its possessor like a head-marking language.
In rare cases, phrases can even be double-marked; in possessive phrases, Turkish marks the possessor
with a genitive case while simultaneously marking the possessed noun with a possessive
suffix, so literally “of-the-woman her-dog”, and a few languages, like Basque and Georgian,
show double-marking in the verb phrase by using both case-marking and polypersonal agreement.
This kind of double-marking is quite rare, since it’s a little redundant to mark the
roles in the phrase twice, but it does crop up occasionally.
It’s also possible for phrases to not show any overt marking, leaving the interpretation
entirely up to word order or just context.
Adpositional phrases frequently have no morphology at all, just a noun and an adposition next
to each other, which is often all that’s needed to understand the intended meaning.
Sometimes zero-marking can also occur in possessive phrases, where the roles aren’t clarified
with any specific morphology but are instead inferred just by putting two nouns in juxtaposition,
and in many isolational languages, word order alone will be enough to clarify which noun
is the subject and which is the object without the need for any case-marking or verb agreement.
Whether a language is head-marking or dependent-marking will go a long way to determine many aspects
of its grammar, so when making a conlang, it’s worth bearing in mind from the very
beginning.
Specifically, decide, ideally as early as possible, whether you want your language to
favor head-marking or dependent marking, but also decide if you want to stick to the prototypical
marking systems or include any exceptions, such as choosing a specific type of phrase
that marks in the opposite way to other phrases, or that takes no marking or even double-marking.
Whatever you decide, create dependent-marking strategies by having adpositions affix onto
the nouns they occur with to become case-markers, and head-marking strategies by having pronouns
affix onto heads.
And finally, keep your marking system in mind when deriving new constructions to keep your
grammar consistent.